After innocent-looking cargo shipments began catching fire at airports and warehouses in Germany, Britain and Poland over the summer, there was little doubt in Washington and Europe that Russia was behind the sabotage.

But in August, White House officials became increasingly alarmed by secretly obtained intelligence suggesting Moscow had a far larger plan in mind: bringing the war in Ukraine to American shores.

The question was how to send a warning to the one man who could stop it: President Vladimir V. Putin of Russia.

In a series of Situation Room briefings, President Biden’s top aides reviewed details of conversations among top officials of the G.R.U., Russia’s military intelligence arm, who were describing shipments of consumer products that burst into flames — in one case, a small electronic massager — as a test run.

Once the Russians understood how the packages made it past air-cargo screening systems, and how long they took to ship, the next step appeared to be sending them on planes bound for the United States and Canada, where they would trigger fires once they were unloaded.

While the main concern was cargo planes, sometimes passenger planes take smaller packages in spare space in their cargo holds.

“The risk of catastrophic error was clear,” Alejandro Mayorkas, the homeland security secretary, said in a recent interview, “that these could catch fire in a fully loaded aircraft.”

In August, Mr. Mayorkas placed new screening restrictions on cargo being shipped into the United States. In October, when the warnings resurged, he quietly pressed the top executives of the largest airlines flying into the United States to accelerate their steps to prevent a midair disaster. Some of those precautions became public at the time; others did not.

But behind the scenes, White House officials were struggling to understand whether Mr. Putin had ordered or was aware of the plot — or if he had been kept in the dark. And a major effort was begun to warn him to end it.

Reaching for a playbook first developed in October 2022 — when the United States believed Russia was considering detonating a nuclear weapon in Ukraine — Mr. Biden dispatched his national security adviser, Jake Sullivan, and the C.I.A. director, William J. Burns, to send a series of warnings to Mr. Putin’s top aides. As one senior official recounted, many paths were needed to ensure the message reached Putin’s ears, and sank in.

The core of the warning was that if the sabotage led to mass casualties in the air or on the ground, the United States would hold Russia responsible for “enabling terrorism.” Mr. Sullivan and Mr. Burns did not specify what that response would be, but made clear it would take the shadow war between Washington and Moscow to new levels.

That shadow war continues, every day, as Russia turns to sabotage in hopes of breaking NATO’s will to support Ukraine, without setting off a full war with the NATO alliance.

It has redefined life in Europe, ending the sense of security that came along with the post-Cold War world. There is now an hour-by-hour search for saboteurs — at airports, seaports and undersea, as well as on the streets of major cities like Berlin, Tallinn and London.

But in this case the warning got through to Mr. Putin, the officials said in describing the secret exchanges with the Kremlin for the first time. And they appear to have had their intended effect: The rash of fires in Europe have ceased, at least for now. But it is unclear whether Mr. Putin ordered a halt, or for how long. And it is possible, officials say, that Russia is using the time to build better, stealthier devices.

Plausible deniability?

The effort to get to Mr. Putin was described by five senior officials interviewed over the past three weeks and who requested anonymity to discuss a sensitive national security threat. In recent days, as the administration prepares to leave office in a week, some of the details of the tense interchanges with the Kremlin have only just been declassified.

While the officials said their effort to avert the worst was successful, it clearly left several of them shaken. As they leave office, they are concerned that Russia’s military, angry at the embarrassing and sometimes deadly Ukrainian attacks around Kursk and other targets inside Russian territory, is now determined to bring the conflict to European and American territory. But they want to do it using techniques that would not risk an all-out conflict with NATO.

The Russians may well have considered the operation a natural — and, in their mind, proportionate — reaction to the Ukrainian attacks on Russian soil, which have been at least partly dependent on U.S.-supplied weapons, including missiles.

To this day the U.S. officials do not know if Mr. Putin ordered the operation, whether he knew about it or whether he only learned of it because of the American warnings.

Several officials said they suspected the plot could have been the work of G.R.U. officers who were responding to general orders to increase the pressure on the United States and its NATO allies. That would be consistent, they said, with past efforts to create plausible deniability for Mr. Putin should the operation go badly.

The incident demonstrated that Mr. Biden and Mr. Putin maintained indirect channels of communication, even though they have not spoken since the Russian attack on Ukraine began in February 2022.

That freeze on direct conversations between Washington and Moscow appears about to end: President-elect Donald J. Trump said on Thursday that Mr. Putin “wants to meet, and we’re setting it up,” though the Kremlin insists there has been no formal conversation. Mr. Trump and his aides are cagey on the question of whether the two men have already talked. They have not said if the conversations will be limited to the Ukraine war or will also include the other elements of the hostile relationship between Washington and Moscow: a brewing nuclear arms race, Russia’s future in Syria and the accelerating shadow war with the West.

News of the air cargo operations seeped out of Europe this summer, and The Wall Street Journal reported in early November that intelligence officials believed Russia’s ultimate goal was to expand the operations to the United States and Canada.

But this account is the first to describe how Mr. Biden’s aides determined that unless they intervened with Mr. Putin directly, the events could lead to a calamity: even an unintended one, if a plane was delayed by bad weather, or the saboteurs got the timing wrong.

“It was a powerful example,” Mr. Mayorkas said, “of the convergence of national security and homeland security.”

Mysterious fires and cable cuts

For the first two years of the war, Russia seemed determined to keep the conflict within Ukraine’s boundaries. Its missiles never strayed into NATO territory. On the one evening when it appeared a missile may have crossed the border into Poland and killed two farmers, Mr. Biden was awakened for fear the two countries were about to stumble into open conflict. To Washington’s relief, it was a false alarm; the awry shot came from the Ukrainians.

That changed in 2024. Cases of sabotage, and suspected sabotage, appeared everywhere: hard-to-explain fires at warehouses, sometimes linked to companies supporting the arming of Ukraine; GPS “spoofing” that paralyzed the navigation systems of shipping and flights across Europe; cuts in undersea fiber-optic cables in which the dragging anchors from Russia’s “shadow fleet” of barges seemed culpable.

Washington helped intelligence officials in Berlin uncover an assassination plot against the chief executive of Germany’s leading arms maker, Rheinmetall. The company is a leading producer of the artillery shells that Ukraine desperately needs.

But when an incendiary device triggered an fire in late July at a DHL cargo facility in Leipzig, the former East German university town, it prompted an immediate investigation. Thomas Haldenwang, the chief of Germany’s domestic intelligence agency, later told the German Parliament that the country had barely averted a plane crash, but he gave no details.

The package had been postmarked from Lithuania, as was another one that went off in Birmingham, England. A third burst into flames at a Polish courier firm.

Inside the White House, the biggest concern came in the form of intelligence about conversations among the G.R.U. American officials will not discuss how they got access to the conversations. But they confirmed the content: The three incendiaries were intended to scope out how DHL and other packages flow, so that the ignition of a highly flammable magnesium-based material could be precisely timed to catch fire.

The conversations indicated that the next step was to get them on planes to the United States and Canada. But the fear that coursed through Situation Room discussions was that an unintended delay — from weather or airplanes circling because of heavy traffic — could mean that the devices went off in midair.

From Washington to Moscow, a warning

In August, the C.I.A. and others concluded that the incendiary devices that went off in Leipzig, Birmingham and Poland were actually part of a “field test” by the G.R.U., as it tried to understand what path packages follow on their way through Europe. The packages were sent from Vilnius, Lithuania, where the Russians retain a significant intelligence presence.

Associates of Mr. Sullivan’s recall him being highly focused on the risk of the attacks in this period, though he said nothing publicly about it. But the conversations among the G.R.U. officials left little doubt where this was headed. One senior official involved in the discussions said it became clear they had to get a message to Mr. Putin, because he was the only one in the Russian system capable of ordering the operation to end. But getting to him meant sending the message through multiple paths.

Mr. Sullivan quietly started a series of calls with his Russian counterpart, Yuriy Ushakov, beginning by noting the Rheinmetall plot. Not surprisingly, Mr. Ushakov denied that Russia was involved — much as Russian officials had denied, in October 2022, that they had been planning for the use of a tactical nuclear weapon.

Then, speaking a bit elliptically about how the United States knew, Mr. Sullivan told Mr. Ushakov that the administration believed that the incendiary devices were also Russia’s responsibility — and that they had put civilian lives in danger. The big concern was the risk of mass casualties, he said, if the packages went off on a cargo plane or a passenger plane.

Mr. Burns, the C.I.A. director who served as American ambassador to Russia two decades ago and is the official who knows Mr. Putin best, made essentially the same case to his intelligence equivalent, Sergey Naryshkin, who runs the S.V.R., and Alexander Bortnikov, the director of the F.S.B., the two most powerful of the Russian intelligence agencies. The thinking was that all of them had regular access to Mr. Putin.

The U.S. officials were careful not to say that the intent of the operation was to bring down an airplane; in fact the devices appeared to be designed to go off on the ground. But the risk of an in-air accident seemed high.

While the immediate crisis was averted, Mr. Biden’s aides acknowledge that the incident revealed a larger problem: that as the war grinds on to its third anniversary, the risks are spilling into new arenas, and taking on new dimensions.

“As big as a Ukraine cease-fire would be it’s far from everything,” said Richard Haass, the former president of the Council on Foreign Relations who has written extensively on what an end to the war might look like

The sabotage, he said, “is all part, of a larger pattern.”

“Russia has turned into a revolutionary actor,” he said. “Russia has turned into a country seeking to undermine the international order. And the real question is: Can a Trump administration do something about that?”

When Donald J. Trump was last president of the United States, the wealthy monarchies of the Persian Gulf had a mostly harmonious relationship with his administration. As Mr. Trump prepares to return to the White House, the leaders of those Gulf countries have generally welcomed him back.

But this time around, the Gulf states and Mr. Trump appear to be diverging on several cornerstone issues, like Israel and Iran. Differences over energy policies could also be a source of friction.

It is unlikely that there will be major tensions or ruptures with U.S. allies in the Gulf. But Mr. Trump will be encountering a region that has seen drastic shifts since Israel launched its war on Gaza in response to the Hamas-led attack of Oct. 7, 2023, in which the Israeli authorities say about 1,200 people were killed and about 250 taken hostage.

The war in Gaza, in which at least 45,000 people have been killed, according to health officials in the enclave, has rippled across the region. In Lebanon, the Iran-backed militant group Hezbollah has been battered by more than a year of fighting against Israel. And in Syria, rebels toppled the regime of Bashar al-Assad.

Now, while Mr. Trump is filling his cabinet with Iran hawks and staunch defenders of Israel, Gulf leaders have publicly been urging a softer stance on Iran and a tougher line on Israel.

They have also been calling on the United States to stay engaged with the region.

For now, the Trump administration has appeared eager to engage with the Gulf powerhouses of Saudi Arabia, Qatar and the United Arab Emirates.

In December, Mr. Trump’s pick as his envoy to the Middle East, Steve Witkoff, was in the Emirati capital, Abu Dhabi, where he attended a Bitcoin conference along with Eric Trump, the president-elect’s son. He also went to Riyadh, Saudi Arabia, where he met with Crown Prince Mohammed bin Salman, Axios reported.

Here’s a closer look at the issues facing Mr. Trump as he navigates an evolving relationship with his traditional Gulf allies.

Engagement in the Mideast

One of the clearest calls in the Gulf for Mr. Trump to avoid an isolationist agenda came from Prince Turki al-Faisal, the former head of Saudi Arabia’s intelligence services.

In an open letter to the U.S. president-elect published in November in The National, an Abu Dhabi-based newspaper, Prince Turki referred to an assassination attempt against Mr. Trump and expressed his belief that “God spared your life” in part so Mr. Trump could continue the work he had started in the Middle East during his first term. That mission was to bring “PEACE, with capital letters,” he wrote.

During his first term, Mr. Trump’s administration brokered the Abraham Accords, which saw several Arab countries establishing ties with Israel.

A similar message to Prince Turki was delivered a few days later by Anwar Gargash, an adviser to Sheikh Mohammed bin Zayed, the U.A.E. president, at a conference in Abu Dhabi.

With the Gulf surrounded by an increasingly turbulent region, Mr. Gargash said, American leadership and partnership remained essential. “We need robust leadership that balances humanitarian concerns with strategic interests,” he said.

Going Harder on Israel

On Israel, the most striking shift in messaging in the Gulf has come from the de facto leader of Saudi Arabia, the crown prince. Speaking at an Arab League summit in Riyadh recently, Prince Mohammed for the first time called the Israeli military campaign in Gaza a “genocide.”

Just before the war in Gaza erupted in October 2023, Saudi Arabia appeared to be on the verge of forging diplomatic relations with Israel without fulfilling its longstanding precondition for doing so — the establishment of a Palestinian state. Such a deal would have reshaped the Middle East.

Under one plan, Saudi Arabia would normalize relations with Israel in exchange for stronger defense ties with the United States and American support for a civilian nuclear program in Saudi Arabia.

But recent statements by Prince Mohammed suggest that any deals are a long way off.

In addition to his statement referring to genocide in Gaza, he has also made it clear that Saudi Arabia will not establish diplomatic relations with Israel until a Palestinian state is created. That is still a distant prospect given strong opposition to such a state within the government of Prime Minister Benjamin Netanyahu of Israel.

“I think that the crown prince wanted to make his position clear and beyond any shadow of a doubt,” said Ali Shihabi, a Saudi businessman who is close to the kingdom’s ruling family.

The United Arab Emirates — a signatory to the Abraham Accords — has also signaled a hardened stance toward Israel.

The U.A.E. foreign minister, Sheikh Abdullah bin Zayed, told his Israeli counterpart last week that the Emirates would “spare no effort supporting Palestinians.”

Despite Saudi Arabia’s public stance on the status of a normalization deal, U.S. diplomats have indicated that the kingdom may be privately open to advancing one under a second Trump presidency — contingent upon a permanent cease-fire in Gaza and a tangible commitment by Israel toward a path to Palestinian statehood.

“All of that is ready to go if the opportunity presents itself with a cease-fire in Gaza as well as understandings on a pathway forward for the Palestinians,” the departing U.S. secretary of state, Antony J. Blinken, said on Wednesday. “So, there’s tremendous opportunity there.”

Détente With Iran?

During Mr. Trump’s first term, both Saudi Arabia and the United Arab Emirates championed his administration’s hawkish stance on Iran, seeing Tehran as a dangerous rival in the region.

They cheered when Mr. Trump withdrew the United States from a nuclear deal with Iran and hailed his decision to authorize the assassination of Qassim Suleimani, the general who directed Iran’s militias and proxy forces around the Middle East, in January 2020.

But the dynamics of the region have changed since Mr. Trump’s first term.

Saudi Arabia and Iran reached an accord in March 2023 that reduced tensions in the Persian Gulf and opened the door to high-level diplomatic contacts.

Bahrain, after years of tension with Iran, has made overtures to the Iranian government, with King Hamad bin Isa al-Khalifa saying there was “no reason to delay” the resumption of diplomatic relations. The tiny island kingdom also condemned Israel’s targeting of Iran last October, when a shadow war between the two countries broke out into the open with tit-for-tat attacks.

For Saudi Arabia, the goal is clear: to create a stable regional environment conducive to Prince Mohammed’s dream of diversifying the oil-dependent Saudi economy. For Iran, decades of economic and political isolation, compounded by rising domestic unrest, have made reconciliation with Riyadh a necessity.

There are also indications that Iran might be open to negotiating with Mr. Trump. Many former officials, pundits and newspaper editorials in Iran have openly called for the government to engage with Mr. Trump.

So far, Mr. Trump, too, appears open at least in charting a different course from the “maximum pressure” campaign of his first term. In November, Elon Musk, a close adviser to Mr. Trump, met with Iran’s ambassador to the United Nations, Iranian officials said.

“We have to make a deal because the consequences are impossible,” Mr. Trump said in September, referring to the threat of Iran’s pursuing nuclear weapons.

Possible Frictions Over Oil

While the Gulf Cooperation Council countries — Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates — appear open to Mr. Trump’s transactional approach to diplomacy, they could find themselves at odds with his economic policies.

A central promise of his campaign was to bolster U.S. oil and gas production, a move that could hurt Gulf economies.

If the United States increases oil production, as Mr. Trump has pledged, producers in the Gulf would have less scope to raise output without prompting a price drop.

“Increased U.S. oil exploration and production will lower prices and jeopardize the oil-driven economies of the Gulf,” Bader al-Saif, an associate fellow at the London-based research institute Chatham House, said in a recent report.

Mr. Trump is also expected to accelerate liquefied natural gas projects, reversing President Biden’s freeze on permits and increasing U.S. exports, particularly to Europe.

Qatar, one of the largest producers of the gas alongside the United States, would most likely be most affected, but it has so far played down its concerns.

President Biden kicks off his final week in office on Monday with a robust defense of his foreign policy, arguing in a speech to be delivered in the afternoon that America has become stronger on his watch.

With just seven days left until he hands over the White House to President-elect Donald J. Trump, Mr. Biden hopes to use his remaining time to frame his historical legacy as a transformational leader who bolstered the United States at home and abroad even in just one term.

The effort gets underway at 2 p.m. on Monday with a speech at the State Department focused on what he sees as his successes in the international arena. He plans to say that he strengthened U.S. alliances both in Europe in the face of Russian aggression as well as in the Asian-Pacific amid the rise of China. At the same time, he plans to argue that America’s adversaries — particularly Russia, China and Iran — are all weaker than when he came to office.

“He’s going to ask the question: is America stronger than we were four years ago? And he’s going to answer the question with a definitive yes,” Jake Sullivan, his national security adviser, said in a preview on “State of the Union” on CNN on Sunday. “Our alliances are stronger, as I said before. Our enemies and competitors are weaker. We kept the nation out of war. Every element of American power is stronger today.”

The speech will be the first this week aimed at presenting the best case for Mr. Biden’s presidency as it comes to an end. He will deliver a broader televised farewell address to the nation in prime time on Wednesday evening, much as many presidents have done. He will also deliver speeches this week on his conservation record and at a farewell ceremony for the commander in chief at Joint Base Myers-Henderson Hall.

On foreign policy, Mr. Biden has presided over a tumultuous time and Mr. Trump blamed him for the wars in Ukraine and Gaza, although no U.S. troops are directly involved on the ground in either place. Some critics said the perception of a world aflame and spinning out of Mr. Biden’s control contributed to the erosion of his political popularity at home and ultimately his withdrawal from the election under pressure.

“The fact that Biden is handing the presidency back to his predecessor is in part a reflection of his foreign policy shortcomings,” said Peter Rough, director of the Center on Europe and Eurasia at the Hudson Institute and a former aide to President George W. Bush.

“For most of his time in office, Biden has been on the defensive, first in Ukraine and then in Gaza,” Mr. Rough continued. “The president’s 1990s-era liberal internationalism may have been well intentioned, but it always felt out of step to me with the power politics of the 2020s.”

Still, a new Gallup poll released on Monday showed that America’s standing in Europe has improved strikingly under Mr. Biden. Of 30 NATO allies surveyed, approval of U.S. leadership rose in all but four since 2020, Mr. Trump’s last year in office. Approval ratings rose by double digits in 20 of the 30 countries. In Germany, for instance, approval of U.S. leadership rose from just 6 percent under Mr. Trump to 52 percent under Mr. Biden.

In pulling U.S. troops out of Afghanistan and extricating America from a the longest war in its history, Mr. Biden finally accomplished what his two predecessors wanted to but did not. But the chaotic nature of the withdrawal did considerable damage to both his and the country’s standing in the world.

Mr. Biden rallied much of the world to stand up to Russia’s unprovoked full-scale invasion of Ukraine and reinvigorated NATO after ties frayed under Mr. Trump, even admitting two new members, Sweden and Finland. He steered tens of billions of dollars worth of American arms to Ukraine that helped thwart Moscow’s attempt to take over the country.

But Mr. Biden was criticized from two different directions; some complained he was too reticent to deliver more powerful weapons for fear of escalating with a nuclear superpower, while others complained that he was investing too much American treasure in someone else’s war. And after its initial stunning success, Ukraine’s defense has stalled and Mr. Trump is now promising to end the war with what are expected to be concessions to President Vladimir V. Putin of Russia.

The war in Gaza that followed the Hamas terrorist attack on Israel on Oct. 7, 2023, was the other dominating crisis of Mr. Biden’s tenure. He stood staunchly by Israel and provided weapons for its all-out assault on Hamas, but eventually grew frustrated with Prime Minister Benjamin Netanyahu of Israel who rebuffed American pressure to do more to curb civilian casualties and relieve humanitarian suffering.

Even now, in his final days, Mr. Biden is straining to seal an elusive cease-fire agreement that would end the fighting and result in the release of Israeli hostages held in Gaza, including a few with American citizenship. Mr. Sullivan said Sunday that U.S. negotiators were “very, very close” to a deal, but it was not clear it could be finalized by next Monday when Mr. Trump takes over.

As with Ukraine, Mr. Biden faced criticism from both directions. From one side, he was accused of not doing more to stop the killing of civilians and called “Genocide Joe” at protests. From the other side, he was faulted for putting pressure on Israel to restrain itself in the face of an existential terrorist threat.

Oliviero Toscani, an Italian photographer who used images of an AIDS patient and death row inmates to break the boundaries of fashion imagery as the creative mastermind of Benetton’s advertising campaigns, died on Monday. He was 82.

His death was announced by his family on Instagram. They did not say where he died or cite a cause of death, but in August Mr. Toscani told the Italian newspaper Corriere della Sera that he had been diagnosed with amyloidosis, a rare and incurable condition in which there is a buildup of protein.

His shock-and-awe campaigns in the 1980s and ’90s helped turn Benetton from a small Italian brand into a global fashion powerhouse, with provocative advertisements that blurred the lines between marketing and activism, high art and consumer industry.

In one ad, an AIDS patient lay on his back, his mouth open, his hands curled on his chest. His dark eyes stared past his family, who had gathered around his deathbed. The patient, David Kirby, looked almost Christ-like.

And there, near the bottom right, a few words hung in a green box: “United Colors of Benetton.”

The advertisement, which ran in the 1990s, was one of the most provocative and divisive in recent fashion history, prompting furious debates over whether Benetton, and Mr. Toscani, were creating art, engaging in advocacy or exploiting the epidemic to sell its clothes.

Notably, Mr. Toscani had the Kirby family’s permission to use a colorized version of the image, which was shot in 1990 by the photographer Therese Frare. The Kirbys said the campaign had helped broaden awareness about AIDS.

“Benetton didn’t use us, or exploit us,” the Kirby family said, maintaining that this was a way for their son’s portrait to be “seen all over the world, and that’s exactly what David wanted.”

Mr. Toscani’s ads were often socially progressive, with images of racially diverse and gay families. They were also meant to shock. He used pictures of horses copulating. He used the bloodstained uniform of a soldier killed in Bosnia-Herzegovina. One ad featured actors dressed as a priest and a nun kissing.

“Advertising agencies make millions by repeating the same old thing,” he told The New York Times in 1995, adding, “We try to go another way.”

Mr. Toscani sometimes crossed the line even for Benetton. He joined the company in 1982 and left in 2000 amid an uproar over an ad campaign that featured photographs of death row inmates across the United States.

He returned as creative director in 2017. But his career at Benetton came to an end in 2020, not because of the calculated and daring risks he had taken in photography and advertising, in which he delighted in his broadside challenges to conventional ideas of respectability. Rather, it was because of an offhand comment he made in a radio interview about a bridge collapse in Italy in which more than 40 people died. “Who cares that a bridge collapsed?” he had said. Though he apologized, Benetton fired him.

Italian politicians and creative leaders honored him in social media tributes on Monday. The designer Valentino Garavani, the creator of Valentino, called him “a visionary who challenged the world through his lens.” The designer Giorgio Armani wrote that “the directness and visual impact of his language set a standard.”

Oliviero Toscani was born in Milan on Feb. 28, 1942. He followed in the footsteps of his father, Fedele Toscani, a photojournalist. Mr. Toscani trained at the Zurich School of Applied Arts and worked as a fashion designer before he joined the Benetton Group as art director in 1982.

His survivors include his wife, Kirsti Moseng Toscani, and their three children, Rocco, Lola and Ali. Mr. Toscani was married twice before and had three other children. Complete information on survivors was not immediately available.

In his final months, Mr. Toscani told the Corriere della Sera that he had lost weight while being treated for amyloidosis and that his sense of taste had declined. Wine tasted different to him, he said. “I am not interested in living like this,” he added.

But in September, he traveled to the Museum fur Gestaltung Zurich for a major retrospective of his work called “Oliviero Toscani: Photography and Provocation.” It closed just over a week before he died.

“I have found out that advertising is the richest and most powerful medium existing today,” he told The Times in 1991. “So I feel responsible to do more than to say, ‘Our sweater is pretty.’”

Elisabetta Povoledo and Matthew Mpoke Bigg contributed reporting.